What is the most specific classification of an organism?

The most specific classification of an organism is species. This classification denotes a group of individuals that can interbreed and produce fertile offspring, making it the most precise category in the biological classification hierarchy. When biologists refer to an organism's species, they are identifying the fundamental unit of biodiversity, which encompasses specific traits and genetic characteristics that distinguish one type of organism from another.

In the taxonomy hierarchy, species is a level below both genus and family, making it narrower in scope. While the genus groups together species that are closely related and share a common ancestor, the family includes multiple genera (plural of genus) that showcase broader similarities among the organisms. Similarly, order is an even larger grouping that includes multiple families. Therefore, the correct answer highlights the most specific taxonomy category, emphasizing its unique identification of individual organisms within the extensive classification system.